When To Fertilize Citrus Trees? Use a simple schedule to ensure that your citrus trees get what they need at the right time. Most Texas soils require additional nitrogen for citrus trees.
Citrus and Climate
About 85 percent of citrus trees grown in Texas are outside the lower Rio Grande Valley, about 100 miles south of Rio Grande River. Citrus fruits, including lemons, citrus fruits and limes, are grown in hardness zones 8 and 10 of the U.S. Department of Agriculture, meaning citrus fruits can be grown successfully in some parts of Texas. Outside this area, periodic frost puts you at a disadvantage, but if you live on the Gulf Coast or in South Texas, you can grow citrus fruits successfully if you provide your trees with winter frost protection.
Citrus and Soil
The soils in the Rio Grande Valley are fertile and generally good for citrus cultivation. They are well drained and range from fine sandy to coarse sandy loam. The soils range from 7.6 to 8 and the groundwater is about 5 feet. Citrus trees do not absorb the most commonly used fertilizers and nutrients if they are not planted in soils with a corresponding pH.
Fertilisers are useless in these circumstances. Do not fertilize plants such as citrus trees unless they show signs of growth. In some valleys, citrus fruits can be grown in soils with a pH of 6 to 8. This is not salty, but a block of potash, a hard layer of lime and calcium carbonate found in many dry soils.
In October, add 1 cup of coarse, water-soluble fertilizer containing 8 to 13 percent nitrogen. Nitrogen levels are the first in a three-digit range of fertilizers sold in the United States.
Apply 2 cups with 8 to 13 percent nitrogen fertilizer to two-year-old trees between February and October. For 3-year-old trees, 4 cups of the same fertilizer are applied every month between February and October. Apply the fertilizer in a circle about 12 cm from the trunk and water it regularly. Pay attention to fertilizers like 13-10-4 in the product.
For 2-year-old trees
For 2-year-old trees, apply 1 cup once a month from February to October. 2 cups per month are valid for 3-year-old trees between February and October. In the first year after transplantation, apply either 1 or 2 cups per month from October to May. Apply a small amount of fertilizer when the first amount of nitrogen is in the range of 17 to 21%, e.g. 21% or 0% to 0% ammonium sulfate fertilizer.
Remember that the first number on the fertilizer packaging indicates the percentage weight of nitrogen. For mature trees that bear fruit, use fertilizer that contains 15 percent or less nitrogen. Apply 1 pound per 1-inch trunk diameter each year. Two cups of dry fertilizer is about 1 pound.
Use fertilizer that contains 20 percent or more nitrogen than the first number in the fertilizer package. In this case, use 3 to 4 pounds for less than 1 inch of trunk width per year. You can apply for the equivalent amount each year by applying in February. Texas A & M University recommends two applications in February (two-thirds of total) and one-third in May. The application could also be divided into three applications in February, May and September.
Sprinkle the fertilizer in a 12 to 18 inch band on the outer spread of each limb. This is where most of the feeding places and roots of the trees are located. The water distributes the fertilizer evenly.